Zero backlash worm gearing for pan and tilt

AI Thread Summary
The discussion focuses on designing a zero backlash worm drive for a pan and tilt mechanism using a stepper motor. Key considerations include achieving a torque transmission of 70 Nm with a motor torque of 1 Nm, while maintaining a position accuracy of 0.1 degrees. Participants mention concepts like "scissors gears" and split worm wheels, which utilize spring preloading to minimize backlash but may increase friction. There is a need for clarity on how to calculate the torque capacity of the worm wheel and shaft specifications, particularly for achieving a target of 100 Nm. The preference is to purchase components from a catalog that meet the zero backlash requirement.
anilks
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I am designing a Pan and tilt drive for with stepper motor as prime mover. We need a zero backlash worm drive to transmit 70 Nm. motor torque is 1 Nm. What are the options.. position accuracy is 0.1 deg.

thanks
 
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I am no expert on it, but I know people use "scissors gears," where one of the meshing gears is actually two gears with a spring preloading them to contact the front-and back-side of the other gear's teeth. I suppose the preload must be large enough to prevent either side coming out of contact during maneuvers. This will cause more friction, but that may also keep the pan/tilt support from moving once it's positioned.
 
Thank you for response. I have come across split worm wheel concept while I was browsing. But what kind of Torque it can transmit (Given the PCD and no of starts). I could not figure out.
 
anilks said:
But what kind of Torque it can transmit
The two halves of the split worm wheel are preloaded by a spring or springs that generate a differential torque between the two halves. The strength of the spring determines the load that can be carried without hysteresis. If the spring is too strong then the worm and wheel will wear at a rate greater than necessary.
 
Thank you. I should have been more specific. How to calculate the torque that can be transmitted. I want to transmit about 100 N.M in a particular application. What should be the Specification of the worm wheel and shaft?

thank you .
 
anilks said:
What should be the Specification of the worm wheel and shaft?
Will you design and build your own worm and wheel, or buy from a catalogue?
 
Baluncore said:
Will you design and build your own worm and wheel, or buy from a catalogue?
I want to buy from catalogue. But looking for zero back lash
Thank you
 
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